Hg-based chalcogenides possess diverse structures, large
nonlinear-optical
(NLO) responses, and suitable birefringences, making them potentially
suitable for numerous crucial criteria of practical application as
infrared (IR) NLO crystals. Here, a new pentanary Hg-based sulfide
K2Ba7HgIn4S16 has been
discovered by a high-temperature solid-state method. It crystallizes
in the orthorhombic P21212
space group, and its one-dimensional structure is constructed by {[In2S7]8–}∞ chains
and isolated [HgS4]6– planar quadrilateral
units located bewteeen the chains, representing a novel type of chalcogenide.
K2Ba7HgIn4S16 exhibits
a moderate NLO effect of 0.5 × AGS at 2.1 μm and a high
laser-induced damage threshold of ∼5.8 × AGS, as well
as a band gap of 2.98 eV, demonstrating that K2Ba7HgIn4S16 is a potential IR NLO material. This
work enriches the structural chemistry of chalcogenides and the family
of Hg-based IR NLO chalcogenides.